Process fob refining and purifying animal tallows



Patented Aug. 14, 1923.

UNITED STATES PATENT oer-ice.

JOHN W. RUWE, OF SAN ANTONIO, TEXAS.

raocnss roa REFINING AND PURIFYING ANIMAL TALLOWS, OILS, FATS, m

. GREASES.

T olall whom it 'ma concern:

Be it known that I. JOHN R. Rowe. a citizen of the United States. residing at 511 West Russell Street, San Antonio. in the Q county of Bexar and State of Texas, have invented certain new and useful Improvements in Processes for Refining and Purifying Animal Tallows, Oils, Fats, and Greases, of which the following is a spoolfication.

This invention relates to a process or refining and purifying animal tallow fats and greases.

Prior to my invention animal fats have been refined by heating the fat to the melting point (approximately 115 F.) and adding a caustic soda solution. This method has not been satisfactory. At the melting point of the fat the caustic soda solution combines too readily with the free fatty acids and semi-saponifies some of the neutral fat producing a grainy oily soap stock. This also precipitates neutral fat with the soap stock and reduces the percentage of yield. Furthermore. it appears impossible by this method to obtain a definite line of separation between the free fatty acids with impurities (soap stock) and the neutral fats. This is apparently due to the formation of $0 sodium alhuminate lay the action of the caustic soda solution on the albumin content of the animal fat. The sodium albuminate is in the. nature of a liquid soap and remains in suspension. This liquid soap clouds the it? line of separation between the neutral fats and the soap stock. permeates the neutral fats. and prevents an economic and perfect separation of the neutral fats and soap stock, even though it is contrarily allowed to settle six to eight hours.

The difliculty had with the above method of refining animal fats has resulted in the production oi impure neutral fats. a great refining lose. more time consume-i and a consrquent cos! of production and high price. in the consumer.

The principal ohicz'tot my invention is to provide an econoo'iic m th d of refining anirnal fats.

Another object of my invention is to provid a method of refining: animal fats whorehy' a pure neutral fat. will e obtained.

1 have discoveoed the phenomena that the dilliculties in refining animal fats by the above method may be eliminated by the Application filed December 20, 1919. Serial No. 340,355.

presence of a vegetable oil during the re.

fining operation. If a quantity of crude vegetable oil. such as cotton seed oil, peanut oil. soya bean oil, sesame oil, coconut oil, rape seed oil, or the like be mixed with the animal fat, and the two refined together, a clear and definite line of separation between the neutral fats and soap stock is obtained, and-the resultant neutral fat is free of the large percentage of impurities heretofore contended with. The presence of a vegetable oil during the' refining of the animal fat reduces the melting point of the mixture and thereby obviates the combination of the caustic soda solution too readily with the free fatty acids and the semi-sap0nification of neutral fat that occurs at higher temperatures. During the refining operation the free fatty acids and albuminous matter contained in the animal fats and free fatty acids contained in the crude vegetable oils gradually combine with the caustic soda solution and produce a clear and positive separation of the free fattyaeicls and albuminous matter. which ;readily and quickly settle out as a soap'stock of plastic coherent nature. This formation ofa plastic coherent soap stock from the mixture of the animal fat and vegetable oil causes a clear-cut line of separation between the neutral fats and the soap stock, thus preventing the entraining of neutral fat in the soap'atock and thereby materially reducing the refining loss. This result is highly advantageous in contriulistinction to the in'dcfi-nite zone of separation between neutral fats and soap stock heretofore experienced in the refining of animal Fats. Because of the clear-cut separation of the neutral fats and soap stock produced by. following my invention, it is possible to obtain a resultant neutral fat product much 'purer and more stable than that heretofore obtained by refining animal fats. It is possible with my process to draw oil the neutral fats within two hours after refining.

in using my invention those skilled in the art should maintain the same relative proportion of constituents as they have utilized heretoi'orv in refining. n refining with cau tic soda sutlicient caustic soda, solution should be added to combine with the free fatty a ids thereby producing a complete and positive separation of the free. fatty g t-ids and impurities contained insaid mix- IOU ture. Refining operators are aware that vithin certain limits the precise proportion .if caustic soda solution to free fatty acids tion. It too small a percentage of vegetable oil is employed the ellcct will benegligible. Less than 3% vegetnlile oil will be of little practical benefit. There is no maximum limit to the percentage of vegetable oil employed. A valuable commercial feature of my invention is the possibility of utilizing a large proportion of vegetable oil when the same. is cheap. relative to animal fats, and vice versa.

in practicing my invention 1 have obtained-good results by employing animal fats and vegetable oil n proportions of 7 to 3. The mixture is placed in a refining tank and heated to 8tl1l0 F. While agitating the melted mixture the liquid caustic soda solution is added. (For example:- if the mixture shows 3% Free fatty acid use (i' Z of 18 Tie. lye). After the caustic soda solution has combined with the free fatty acid and albuminous matter, the tempera ture is gradually rai ed from 20 I to effect a complete separation. Then-upon the agitation is stopped and the soap hlfit'k permitted to settle. The neutral material may then he drawn off.

My invention p rtains primarily to the discovery that an economical and proper relining of animal fats may be accomplished by employing the presence of vegetable oils.

'lo tliose skilled in the art it will liorlcnr that various minor changes may he made in the process outlined herein without 1|cpurting from my invention. 1

I claim:

l. proce s of refining animal fat, conr prising mixing with animal fat a vegetable oil. limiting the mixture lwlnw the melting point ol" the animal fat when free li'iun the vegetable oil, adding sufficient caustic soda solutionto combine with the free fatty acid 110 F., adding caustic soda solution, in

creasing. the temperature ap roximatiely 20 to 40 F., and allowing t e mixture to stand.

A process of refining animal fat which consists in heating a mixture of animal fat and vegetable oil to approximately 80 to 110 F adding sufficient caustic soda solution to neutralize the free fatty acid but not such a quantity of said solution as would saponify the neutral fat, increasing the temperature approximately 20 to 40 F.', and permitting the mixture to stand until stratification takes place. i

4. A process of refining animal fat oomprising mixing with tin animal fat a vegetablc oil. adding sutiicient caustic solution to combine with the free fatty acids, allowing.

the mixture to stand until the neutral fat is separated from the soap stock and Withtllil\\'lll,L the neutral fat fromsaid soap stock.

5. ln :1 process for Nfililllfl animal oils for production of a ncutrul fat. lowering the melting oint of animal fat by mixing there it h a vegetable OiLheatingthe mixture to temperature lower than the melting temperuturc of tin l'retanimal fat, adding suf lll'll'lll rnu titsoda solution to combine with the l'ri-ifatty acids present but not ltt'l1 a quantity as mild suponit the neutral tat, Hlltl tliilltllllii! the neutral fat from the .lllllH'F.

l:- i --t imony whereof I atlix my signature. 

